Method of reducing transmission power and terminal thereof

ABSTRACT

A method of reducing transmission power. The method according to one embodiment includes calculating a maximum power reduction (MPR) on a maximum output power for transmission with non-contiguous resource allocation in a single component carrier; and transmitting a signal. The MPR is calculated differently depending on a ratio A which is a ratio of a number of simultaneously transmitted resource blocks in a channel bandwidth (NRB_alloc) to a number of aggregated resource blocks in a fully allocated aggregated channel bandwidth (NRB_agg). The MPR is calculated using a first equation when the ratio A is greater than 0 and less than or equal to 0.33. The MPR is calculated using a second equation when the ratio A is greater than 0.33 and less than or equal to 0.77. The MPR is calculated using a third equation when the ratio A is greater than 0.77 and less than or equal to 1.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a Continuation of co-pending U.S. patent applicationSer. No. 14/527,478, filed on Oct. 29, 2014, which is a continuation ofU.S. patent application Ser. No. 13/543,548, filed on Jul. 6, 2012 (nowU.S. Pat. No. 8,879,493, issued on Nov. 4, 2014), which claims priorityunder 35 U.S.C. §119(e) to U.S. Provisional Application Nos. 61/568,150,filed on Dec. 7, 2011, 61/579,639 filed on Dec. 22, 2011 and 61/591,277filed on Jan. 27, 2012 and under 35 U.S.C. §119(a) to Application No.10-2012-0018182, filed in the Republic of Korea on Feb. 22, 2012, theentire contents of all of the above applications are hereby incorporatedby reference. This application is also related to U.S. patentapplication Ser. No. 14/527,619 filed on Oct. 29, 2014, which is anothercontinuation of U.S. patent application Ser. No. 13/543,548.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present disclosure relates to a method of reducing transmissionpower and a terminal thereof.

2. Discussion of the Related Art

Recently, studies on a next-generation multimedia radio communicationsystem have been actively conducted. The radio communication systemrequires a system that can process various information including images,radio data, etc. in lieu of services mainly using voice and transmit theinformation. The object of the radio communication system enables aplurality of users to perform reliable communication regardless oflocation and mobility. However, wireless channels suffer from severalproblems such as path loss, shadowing, fading, noise, limited bandwidth,power limitation of terminals and inter-user interference. Otherchallenges in the design of the radio communication system includeresource allocation, mobility issues related to rapidly changingphysical channels, portability and design for providing security andprivacy.

When a transmission channel suffers from deep fading, if another versionor replica of a signal transmitted to a receiver is not separatelytransmitted to the receiver, it is difficult for a receiver to determinethe transmitted signal. A resource corresponding the separate version orreplica is called as a diversity, and the diversity is one of the mostimportant factors contributing to reliable transmission. If thetransmission capacity or transmission reliability of data can bemaximized using the diversity, and a system for implementing a diversityusing multiple transmit and receive antennas is referred to as amultiple input multiple output (MIMO) system.

Techniques for implementing the diversity in the MIMO system are spacefrequency block code (SFBC), space time block code (STBC), cyclic delaydiversity (CDD), frequency switched transmit diversity (FSTD), timeswitched transmit diversity (TSTD), precoding vector switching (PVS),spatial multiplexing (SM), etc.

Meanwhile, one of systems considered after the 3rd generation system isan orthogonal frequency division multiplexing (OFDM) system capable ofreducing an inter-symbol interference effect with low complexity. TheOFDM system converts serially input data into N parallel data andtransmits the N parallel data respectively carried by N orthogonalsubcarriers. The subcarrier maintains orthogonality in terms offrequencies. Orthogonal frequency division multiple access (OFDMA)refers to Orthogonal Frequency Division Multiple Access (OFDMA) refersto a multiple access method of realizing multi-access by independentlyproviding users with some of available subcarriers in a system usingOFDM as a modulation method.

FIG. 1 illustrates a radio communication system.

Referring to FIG. 1, the radio communication system includes at leastone base station (BS) 20. Each of the BSs 20 provides a communicationservice for a specific terrestrial area (generally, referred to as acell) 20 a, 20 b or 20 c. The cell may be divided into a plurality ofareas (also referred to as sectors). A user equipment (UE) 10 may befixed or have mobility. The UE 10 may be called as other terms includinga mobile station (MS), a subscriber station (SS), a wireless device, apersonal digital assistant (PDA), a wireless modem, a handheld device,etc. The BS 20 generally refers to a fixed station communicating withthe UEs 10, and may be called as other terms including an evolved-NodeB(eNB), a base transceiver system, an access point, etc.

Hereinafter, downlink (DL) means communication from a BS to a UE, anduplink (UL) means communication from a UE to a BS. In the DL, atransmitter may be a portion of the BS and a receiver may be a portionof the UE. In the UL, a transmitter may be a portion of the UE and areceiver may be a portion of the BS.

The radio communication system may be any one of a multiple inputmultiple output (MIMO) system, a multiple input single output (MISO)system, a single input single output (SISO) system and a single inputmultiple output (SIMO). The MIMO system uses a plurality of transmitantennas and a plurality of receive antenna. The MISO system uses aplurality of transmit antennas and one receive antenna. The SISO systemuses one transmit antenna and one receive antenna. The SIMO system usesone transmit antenna and a plurality of receive antennas.

Hereinafter, the transmit antenna means a physical or logical antennaused to transmit one signal or stream, and the receive antenna means aphysical or logical antenna used to receive one signal or stream.

Meanwhile, a long term evolution (LTE) system defined by 3rd generationpartnership project (3GPP) employs the MIMO. Hereinafter, the LTE systemwill be described in detail.

FIG. 2 illustrates a structure of a radio frame in 3GPP LTE.

Referring to FIG. 2, the radio frame is composed of ten subframes, andone subframe is composed of two slots. The slots in the radio frame aredesignated by slot numbers from 0 to 19. The time at which one subframeis transmitted is referred to as a transmission time interval (TTI). TheTTI may be called as a scheduling unit for data transmission. Forexample, the length of one radio frame may be 10 ms, the length of onesubframe may be 1 ms, and the length of one slot may be 0.5 ms.

The structure of the radio frame is merely an example, and the number ofsubframes included in the radio frame, the number of slots included inthe subframe, etc. may be variously modified.

FIG. 3 is an exemplary view illustrating a resource grid for one UL slotin the 3GPP LTE.

Referring to FIG. 3, the UL slot includes a plurality of OFDM symbols ina time domain, and includes N^(UL) resource blocks (RBs) in a frequencydomain. The OFDM symbol is used to represent one symbol period, may becalled as an SC-FDMA symbol, OFDMA symbol or symbol period depending ona system. The BS includes a plurality of subcarriers in the frequencydomain as a resource allocation unit. The number N^(UL) of RBs includedin the UL slot depends on the UL transmission bandwidth configured in acell. Each element on a resource grid is referred to as a resourceelement.

Although it has been illustrated in FIG. 3 that one RB includes a 712resource element composed of 7 OFDM symbols in the time domain and 12subcarriers in the frequency domain, the number of subcarriers and thenumber of OFDM symbols in the RB are not limited thereto. The number ofOFDM symbols and the number of subcarriers in the RB may be variouslychanged. The number of OFDM symbols may be changed depending on thelength of a cyclic prefix (CP). For example, the number of OFDM symbolsin a normal CP is 7, and the number of OFDM symbols in an extended CP is6.

The resource grid for one UL slot in the 3GPP LTE of FIG. 3 may beapplied to the resource grid for one DL slot.

FIG. 4 illustrates a structure of a DL subframe.

The DL subframe includes two slots in the time domain, and each of theslots includes seven OFDM symbols in the normal CP. Maximum three OFDMsymbols (maximum four OFDM symbols for a bandwidth of 1.4 MHz) prior toa first slot in the subframe become a control region to which controlchannels are allocated, and the other OFDM symbols become a data regionto which a downlink shared channel (PDSCH) is allocated. The PDSCH meansa channel through which a BS transmits data to a UE.

A physical downlink control channel (PDCCH) may carry resourceallocation (also referred to as DL grant) and transmission format on adownlink-shared channel (DL-SCH), resource allocation information (alsoreferred to as UL grant) on a uplink-shared channel (UL-SCH), paginginformation on a paging channel (PCH), system information on the DL-SCH,resource allocation of an upper layer control message such as a randomaccess response transmitted on the PDSCH, a set of transmission powercontrol (TPC) for individual UEs in a UE group, activation of a voiceover Internet protocol (VoIP), etc. The control information transmittedthrough the PDCCH as described above is referred as downlink controlinformation (DCI).

FIG. 5 illustrates an example of the structure of the uplink subframe inthe 3GPP LTE.

Referring to FIG. 5, the uplink subframe may be divided into a controlregion in which a physical uplink control channel (PUCCH) carryinguplink control information is allocated and a data region in which aphysical uplink shared channel (PUSCH) carrying uplink data informationis allocated. To maintain a single carrier property, RSs allocated toone UE are contiguous in the frequency domain. The one UE cannottransmit the PUCCH and the PUSCH at the same time.

The PUCCH for one UE is allocated as an RB pair in a subframe. RBsconstituting the RB pair occupy different subcarriers in first andsecond slots, respectively. The frequency occupied by each of the RBsconstituting the RB pair is changed at a boundary between the slots. TheUE transmits uplink control information through different subcarriersaccording to time, thereby obtaining a frequency diversity gain.

The uplink control information transmitted on the PUCCH includes hybridautomatic repeat request (HARQ) acknowledgement (ACK)/negativeacknowledgement (NACK), channel quality indicator indicating a downlinkchannel state, scheduling request (SR) that is an uplink radio resourceallocation request, etc.

The PUSCH is mapped to the UL-SCH that is a transport channel. Uplinkdata transmitted on the PUSCH may be a transport block that is a datablock for the UL-SCH transmitted for the TTI. The transport block may beuser information, or the uplink data may be multiplexed data. Themultiplexed data may be data obtained by multiplexing the transportblock for the UL-SCH and control information. For example, the controlinformation multiplexed by the data may include CQI, PMI, HARQ ACK/NACK,RI, etc. The uplink data may be composed of only the controlinformation.

Meanwhile, a high data transmission rate is required, and the mostgeneral and stable plan for solving the high data transmission rate isto increase a bandwidth.

However, frequency resources are currently in a saturation state,various technologies are partially used in a wide frequency band. Forthis reason, carrier aggregation (CA) has been introduced as a plan forsecuring a wideband bandwidth in order to satisfy the requirement of thehigh data transmission rate. Here, the CA is a concept of designing tosatisfy general requirements that an independence system is operable ineach of the scattered bands and binding a plurality of bands using onesystem. In the CA, the band in which the independent system is operableis defined as a component carrier (CC).

The CA is employed not only in the LTE system but also in theLTE-advanced (hereinafter, referred to as an ‘LTE-A’) system.

Carrier Aggregation

A carrier aggregation system refers to a system that forms a wide bandby aggregating one or more carriers having a bandwidth narrower than adesired wideband when a radio communication system intends to supportthe wideband. The carrier aggregation system may be called as otherterms including a multiple carrier system, a bandwidth aggregationsystem, etc. The carrier aggregation system may be divided into acontiguous carrier aggregation system in which carriers are contiguousand a non-contiguous carrier aggregation system in which carriers areseparated from one another. Hereinafter, when the carrier aggregationsystem is simply called as a multiple carrier system or carrieraggregation system, it should be understood that the carrier aggregationsystem includes both cases in which component carriers are contiguousand in which component carriers are non-contiguous.

In the contiguous carrier aggregation system, a guard band may existbetween carriers. When one or more carriers are aggregated, the carriersto be aggregated may use the bandwidth used in a conventional system asit is for the purpose of backward compatibility with the conventionalsystem. For example, the 3GPP LTE system supports bandwidths of 1.4 MHz,3 MHz, 5 MHz, 10 MHz, 15 MHz and 20 MHz. Alternatively, the 3GPP LTEdoes not use the bandwidth used in the conventional system as it is butmay form a wideband by defining a new bandwidth.

In the carrier aggregation system, the UE may simultaneously transmit orreceive one or a plurality of carriers according to its capacity.

FIG. 6 illustrates an example of performing communication under a singlecomponent carrier situation. FIG. 6 may correspond to an example ofperforming communication in an LTE system.

Referring to FIG. 6, a general frequency division duplex (FDD) radiocommunication system transmits/receives data through one downlink bandand one uplink band corresponding thereto. The BS and the UEtransmits/receive data and/or control information scheduled as asubframe unit. The data is transmitted/received through the data regionconfigured in the uplink/downlink subframe, and the control informationis transmitted/received through the control region configured in theuplink/downlink subframe. To this end, the uplink/downlink subframecarries signals through various physical channels. Although the FDDradio communication system has been mainly described in FIG. 6, theaforementioned description may be applied to a time division duplex(TDD) radio communication system by dividing a radio frame intouplink/downlink radio frames in the time domain.

FIG. 7 illustrates an example of performing communication under amultiple component carrier situation. FIG. 7 may correspond to anexample of performing communication in an LET-A system.

The LTE-A system uses a carrier aggregation or bandwidth aggregationusing a wider uplink/downlink bandwidth by aggregating a plurality ofuplink/downlink frequency blocks so as to use a wider frequency band.Each of the frequency blocks is transmitted using a component carrier(CC). In this specification, the CC may mean a frequency block forcarrier aggregation or a central carrier of the frequency blockaccording to the context, and the frequency block and the centralcarrier are used together.

On the other hand, the 3GPP LTE system supports a case in which theuplink/downlink bandwidths are configured differently, but supports oneCC in each of the uplink/downlink bandwidths. The 3GPP LTE systemsupports a maximum bandwidth of 20 MHz, and supports only one CC in eachof the uplink/downlink bandwidths. Here, the uplink/downlink bandwidthsmay be different from each other.

However, the spectrum aggregation (bandwidth aggregation or carrieraggregation) supports a plurality of CCs. For example, if five CCs areallocated as the granularity of a carrier unit having a bandwidth of 20MHz, the spectrum aggregation can support a maximum bandwidth of 100MHz.

A pair of DL CC or UL CC and DL CC may correspond to one cell. The onecell generally includes one DL CC and optionally includes UL CC.Therefore, it may be considered that the UE communicating with the BSthrough a plurality of DL CCs receive services from a plurality ofserving cells. The DL is composed of a plurality of DL CCs, but the ULmay use only one CC. In this case, it may be considered that the UEreceives services from a plurality of serving cells in the DL andreceives a service from one serving cell in the UL.

In this meaning, the serving cell may be divided into a primary cell anda secondary cell. The primary cell operates at a primary frequency, andis used to perform an initial connection establishment process,connection re-establishment process or handover process of the UE. Theprimary cell is also referred to as a reference cell. The secondary celloperates at a secondary frequency, and may be configured after RRCconnection is established. The secondary cell may be used to provide anadditional radio resource. At least one primary cell is alwaysconfigured, and the secondary cell may be added/modified/cancelled byupper layer signaling (e.g., an RRC message).

Referring to FIG. 7, five CCs having a bandwidth of 20 MHz may beaggregated in each of the UL/DL, thereby supporting a bandwidth of 100MHz. CCs may be adjacent or non-adjacent to one another in the frequencydomain. For convenience, FIG. 9 illustrates a case in which thebandwidths of UL and DL CCs are identical and symmetric to each other.However, the bandwidth of each of the CCs may be independentlydetermined. For example, the bandwidth of the UL CC may be configured as5 MHz(UL CC0)+20 MHz(UL CC1)+20 MHz(UL CC2)+20 MHz(UL CC3)+5 MHz(ULCC4). Asymmetric carrier aggregation may be implemented in which thenumber of UL CCs is different from that of DL CCs. The asymmetriccarrier aggregation may be formed due to limitation of an availablefrequency band or may be artificially formed by network configuration.For example, although the frequency band of the entire system iscomposed of N CCs, the frequency band received by a specific UE may belimited to M(<N) CCs. Various parameters for the CA may be configured ina cell-specific, UE group-specific or UE-specific manner.

Although it has been illustrated in FIG. 7 that the UL and DL signalsare respectively transmitted through CCs mapped one by one, the CCthrough which a signal is substantially transmitted may be changeddepending on the network configuration or kind of signal.

For example, when a scheduling command is downlink-transmitted throughthe DL CC1, data according to the scheduling data may be transmittedthrough another DL CC or UL CC. Control information related on the DL CCmay be uplink-transmitted through a specific UL CC regardless of thepresence of mapping. Similarly, DL control information may also betransmitted through a specific DL CC.

FIG. 8 illustrates a usage example of Band 13 defined in the LTE systemwhen the Band 13 is used in U.S.A. Here, the Band 13 refers to afrequency band having a DL bandwidth of 746 to 756 MHz and a ULbandwidth of 777 to 787 MHz.

Referring to FIG. 8, as the frequency policies for each country and foreach region are separately established, there occurs a case where anadjacent frequency band of the frequency band used by terminals shouldbe protected for each country and for each region. As can be seen inFIG. 8, a frequency band for public safety in an adjacent band of theBand 13, i.e., a public safety (PS) band is specified in U.S.A, andinterface in the PS band, caused due to another system, is restricted toa certain numerical value or less.

However, if frequency bands in the LTE system are placed as shown inFIG. 8, and each UE transmits a signal using general power, thetransmitted signal cannot satisfy requirements for emission specified inthe corresponding country.

That is, if a signal is transmitted in the Band 13, unwanted emissionoccurs in an adjacent band. Therefore, the adjacent band is interfereddue to the unwanted emission.

SUMMARY OF THE INVENTION

Therefore, an aspect of the detailed description is to provide a methodof reducing transmission power and a terminal thereof, which can limitpower for maximum transmit power.

Another aspect of the detailed description is to provide a method ofreducing transmission power and a terminal thereof, which can limitpower for maximum transmit power in carrier aggregation.

Still another aspect of the detailed description is to provide a methodof reducing transmission power and a terminal thereof, which can limitpower for maximum transmit power in a clustered discrete Fouriertransform-spread-orthogonal frequency division multiplexing (DFT-s-OFDM)scheme.

To achieve these and other advantages and in accordance with the purposeof this specification, as embodied and broadly described herein, thereis provided a method of reducing transmission power, the methodincluding: performing maximum power reduction (MPR) on maximum outputpower for a signal to be transmitted, for multi-cluster transmission ina single component carrier; and transmitting the signal, wherein the MPRis performed differently depending on a resource allocation ratio A,wherein the resource allocation ratio A is defined as a ratio betweenNa_(RB) _(—) _(agg) and N_(RB) _(—) _(alloc), and wherein the N_(RB)_(—) _(agg) represents the number of resource blocks (RBs) in a channelband, and the N_(RB) _(—) _(alloc) represents the total number of RBstransmitted at the same time.

The method may further include receiving information on an uplinkresource allocated by a base station.

The uplink resource for transmission may belong to a specific class ofan intra-band contiguous carrier aggregation (CA) band.

Additional adjacent channel leakage ratio (ACLR) and spurious emission(SE) through network signaling performed from the base station may notbe defined with respect to the intra-band contiguous CA band.

The method may further include receiving system information from thebase station.

The system information may contain at least one of information on anoperating band, information on an uplink bandwidth and information on anuplink carrier frequency, and the information on the uplink bandwidthmay contain information on the number of RBs.

When it is identified that the uplink resource for transmission belongsto the specific class of the intra-band contiguous CA band based on thesystem information, it may be determined that the additional ACLR and SEare not defined by the network signaling.

When it is identified that the uplink resource for transmission belongsto the specific class of the intra-band contiguous CA band based on thesystem information, it may be determined not to consider the additionalACLR and SE received through the network signaling.

The maximum output power for the signal to be transmitted may be definedaccording to the class of the intra-band contiguous CA band.

When the resource allocation ratio A is greater than 0 and smaller thanor identical to 0.33, the MPR may be defined as (8.0−10.12*A)dB. Whenthe resource allocation ratio A is greater than 0.33 and smaller than oridentical to 0.77, the MPR may be defined as (5.67−3.07*A)dB. When theresource allocation ratio A is greater than 0.77 and smaller than oridentical to 1.0, the MPR may be defined as 3.31 dB.

The value of MPR may be defined in consideration of ACLR of an adjacentchannel for UTRA, ACRL of an adjacent channel for E-UTRA, generalspectrum emission mask (SEM) and general SE. The value of MPR is a valuerequired to simultaneously transmit a PUSCH and a PUCCH. Meanwhile,A-MPR may be further defined under a assumption of an additionalunwanted emission. In general, the A-MPR is determined in considerationof an additional SEM and an additional SE, if a terminal transmit asignal in a specific operating band.

To achieve these and other advantages and in accordance with the purposeof this specification, as embodied and broadly described herein, thereis provided a terminal including: a transmitter configured to transmitthe signal, wherein the MPR is performed differently depending on aresource allocation ratio A, wherein the resource allocation ratio A isdefined as a ratio between N_(RB) _(—) _(agg) and N_(RB) _(—) _(alloc),and wherein the N_(RB) _(—) _(agg) represents the number of RBs in achannel band, and the N_(RB) _(—) _(alloc) represents the total numberof RBs transmitted at the same time, wherein the MPR is performeddifferently depending on a resource allocation ratio A, wherein theresource allocation ratio A is defined as a ratio between N_(RB) _(—)_(agg) and N_(RB) _(—) _(alloc), and wherein the N_(RB) _(—) _(agg)represents the number of RBs in a channel band, and the N_(RB) _(—)_(alloc) represents the total number of RBs transmitted at the sametime.

Further scope of applicability of the present application will becomemore apparent from the detailed description given hereinafter. However,it should be understood that the detailed description and specificexamples, while indicating preferred embodiments of the invention, aregiven by way of illustration only, since various changes andmodifications within the spirit and scope of the invention will becomeapparent to those skilled in the art from the detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate exemplary embodiments andtogether with the description serve to explain the principles of theinvention.

In the drawings:

FIG. 1 illustrates a radio communication system;

FIG. 2 illustrates a structure of a radio frame in 3rd generationpartnership project long term evolution (3GPP LTE);

FIG. 3 is an exemplary view illustrating a resource grid for one uplinkslot in the 3GPP LTE;

FIG. 4 illustrates a structure of a downlink subframe;

FIG. 5 illustrates an example of the structure of the uplink subframe inthe 3GPP LTE;

FIG. 6 illustrates an example of performing communication under a singlecomponent carrier situation;

FIG. 7 illustrates an example of performing communication under amultiple component carrier situation;

FIG. 8 illustrates a usage example of Band 13 defined in the LTE systemwhen the Band 13 is used in U.S.A;

FIG. 9 is an exemplary diagram illustrating a method of limitingtransmission power of a terminal;

FIG. 10 is an exemplary diagram illustrating another method of limitingtransmission power of a terminal;

FIG. 11 is a block diagram illustrating a single carrier-frequencydivision multiple access (SC-FDMA) transmission scheme that is an uplinkaccess scheme employed in the 3GPP LTE;

FIG. 12 is a block diagram a clustered discrete Fouriertransform-spread-orthogonal frequency division multiplexing (DFT-s-OFDM)transmission method employed as an uplink access method in theLTE-advanced standard;

FIG. 13 illustrates a scenario in which a physical uplink shared channel(PUSCH) is transmitted by being divided into several cluster units in asingle component carrier;

FIG. 14 illustrates an adjacent channel leakage ratio (ACLR);

FIGS. 15A to 15D illustrate simulations respectively obtained by usingquadrature phase-shift keying (QPSK) and 16-quadrature amplitudemodulation (QAM), and illustrate maximum power reductions (MPRs)according to the simulations;

FIG. 16 illustrates MPRs according to simulation results, when multipleclusters are simultaneously transmitted through a single componentcarrier; and

FIG. 17 is a configuration block diagram of a terminal according to anexemplary embodiment.

DETAILED DESCRIPTION OF THE INVENTION

The following technology may be used in various multiple access schemessuch as code division multiple access (CDMA), frequency divisionmultiple access (FDMA), time division multiple access (TDMA), orthogonalfrequency division multiple access (OFDMA) and single carrier-frequencydivision multiple access (SC-FDMA). The CDMA may be implemented by aradio technology such as universal terrestrial radio access (UTRA) orCDMA2000. The TDMA may be implemented by a radio technology such as aglobal system for mobile communications (GSM)/general packet radioservice (GPRS)/enhanced data rates for GSM evolution (EDGE). The OFDMAmay be implemented by a radio technology such as institute of electricaland electronics engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX),IEEE 802.20 or evolved UTRA (E-UTRA). The UTRA is a portion of auniversal mobile telecommunications system (UMTS). 3rd generationpartnership project (3GPP) long term evolution (LTE) is a portion of anevolved UMTS (E-UMTS) using the E-UTRA, which employs the OFDMA indownlink and the SC-FDMA in uplink. LTE-advanced (LTE-A) is an evolutionof the 3GPP LTE.

Technical terms used in this specification are used to merely illustratespecific embodiments, and should be understood that they are notintended to limit the present disclosure. As far as not being defineddifferently, all terms used herein including technical or scientificterms may have the same meaning as those generally understood by anordinary person skilled in the art to which the present disclosurebelongs to, and should not be construed in an excessively comprehensivemeaning or an excessively restricted meaning. In addition, if atechnical term used in the description of the present disclosure is anerroneous term that fails to clearly express the idea of the presentdisclosure, it should be replaced by a technical term that can beproperly understood by the skilled person in the art. In addition,general terms used in the description of the present disclosure shouldbe construed according to definitions in dictionaries or according toits front or rear context, and should not be construed to have anexcessively restrained meaning.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the invention. Itwill be further understood that the terms “includes” and/or “including,”when used in this specification, specify the presence of statedfeatures, integers, steps, operations, elements, and/or components, butdo not preclude the presence and/or addition of one or more otherfeatures, integers, steps, operations, elements, components, and/orgroups thereof.

It will be understood that, although the terms “first,” “second,” etc.may be used herein to describe various elements, these elements shouldnot be limited by these terms. These terms are only used to distinguishone element from another element. Thus, a “first” element discussedbelow could also be termed as a “second” element without departing fromthe teachings of the present invention.

It will be understood that when an element is referred to as being“coupled” or “connected” to another element, it can be directly coupledor connected to the other element or intervening elements may also bepresent. In contrast, when an element is referred to as being “directlycoupled” or “directly connected” to another element, there are nointervening elements present.

In the drawings, the thickness of layers, films and regions areexaggerated for clarity. Like numerals refer to like elementsthroughout.

Description will now be given in detail of the exemplary embodiments,with reference to the accompanying drawings. For the sake of briefdescription with reference to the drawings, the same or equivalentcomponents will be provided with the same reference numbers, anddescription thereof will not be repeated. It will also be apparent tothose skilled in the art that various modifications and variations canbe made in the present invention without departing from the spirit orscope of the invention. Thus, it is intended that the present inventioncover modifications and variations of this invention provided they comewithin the scope of the appended claims and their equivalents.

Hereinafter, although a terminal is shown in the drawings, the UE may becalled as a user equipment (UE), mobile equipment (ME), mobile station(MS), user terminal (UT), subscriber station (SS), wireless device,handheld device or access terminal (AT). The UE may be a portable devicehaving a communication function, such as a cellular phone, personaldigital assistant (PDA), smart phone, wireless modem or notebookcomputer, or may be a device that cannot be carried, such as a personalcomputer (PC) or vehicle mounting device.

FIG. 9 is an exemplary diagram illustrating a method of limitingtransmission power of a terminal. FIG. 10 is an exemplary diagramillustrating another method of limiting transmission power of aterminal.

Before the method of limiting transmission power of a terminal isdescribed with reference to FIG. 9, the maximum power actually availablefor the terminal in an LTE system is briefly expressed as follows.Pcmax=Min(Pemax,Pumax)  Expression 1

Here, the Pcmax denotes maximum power (actual maximum transmit power)that the terminal can transmit to a corresponding cell, and the Pemaxdenotes maximum power available in a corresponding cell on which a basestation (BS) performs signaling. The Pumax denotes the maximum power(P_(PowerClass)) of the terminal itself in consideration of maximumpower reduction (hereinafter, referred to as MPR), additive-MPR(hereinafter, referred to as A-MPR), etc.

The maximum output power is changed depending on a channel band. In thecase of intra-band carrier aggregation (CA), the operating band isdefined as shown in the following table.

TABLE 1 Uplink Operating Band Downlink Operating Band RS Reception/UE BSTransmission/UE E-UTRA E-UTRA Transmission Reception Duplex CA Band BandF_(UL) _(—) _(low)-F_(UL) _(—) _(high) F_(DL) _(—) _(low)-F_(DL) _(—)_(high) Mode CA_1 1 1920 MHz-1980 MHz 2110 MHz-2170 MHz FDD CA_40 402300 MHz-2400 MHz 2300 MHz-2400 MHz TDD

In Table 1, the F_(UL) _(—) _(low) means the lowest frequency in theuplink operating band, and the F_(UL) _(—) _(high) means the highestfrequency in the uplink operating band.

The FDD is an abbreviation for frequency division Duplex, and the TDD isan abbreviation for time division duplex.

Meanwhile, CA band classes and protection bands corresponding theretoare shown in the following table.

TABLE 2 CA Configuration Maximum Number band of Aggregation of ComponentProtection Band class Transmission Band Carriers BW_(GB) A N_(RB) _(—)_(agg) ≦ 100 1 0.05 BW_(Channel) B N_(RB) _(—) _(agg) ≦ 100 2 Undecided(FFS: For Further Study) C 100 < N_(RB) _(—) _(agg) ≦ 2 0.05 max 200 D200 < N_(RB) _(—) _(agg) ≦ Undecided (FFS: Undecided (FFS: [300] ForFurther Study) For Further Study) E [300] < Undecided (FFS: Undecided(FFS: N_(RB) _(—) _(agg) ≦ [400] For Further Study) For Further Study) F[400] < Undecided (FFS: Undecided (FFS: N_(RB) _(—) _(agg) ≦ [500] ForFurther Study) For Further Study)

In Table 2, the square bracket [ ] is not surely specified yet, and maybe changed. The N_(RB) _(—) _(agg) denotes the number of resource blocks(RBs) aggregated in an aggregation channel band.

In the channel band class C for the intra-band CA shown in Table 2, themaximum output power in an arbitrary transmission band may be defined asshown in the following table. That is, if the channel band for theintra-band CA is defined as Class C, the maximum output power may bedefined as shown in the following table.

TABLE 3 EUTRA Class 1 Tolerance Class 2 Tolerance Class 3 ToleranceClass 4 Tolerance Band (dBm) (dB) (dBm) (dB) (dBm) (dB) (dBm) (dB) CA_1C23 +2/−2   CA_40C 23 +2/[−2]

In Table 3, the tolerance represents an allowable error. In Table 3, thesquare bracket [ ] is not surely specified yet, and may be changed.Here, the CA_(—)1C means an operating band CA_(—)1 in Table 1 in theclass C, and the CA_(—)40C means an operating band CA_(—)40 in Table 1in the class C.

The maximum output power described above expresses a value measuredduring the length (1 ms) of one subframe in an antenna of each UE.

In the current LTE system, the maximum power (P_(PowerClass)) of theterminal itself is defined as Power Class 3, which means power of 23dBm.

Meanwhile, the MPR means the amount of power reduction for the maximumtransmit power defined with respect to a specific modulation order orthe number of RBs so as to satisfy RF requirements (a spectrum emissionmask (SEM), an adjacent channel leakage ratio (ACLR), etc) defined inthe standard. The A-MPR means the amount of power reduction for themaximum transmit power defined due to regional characteristics.

Thus, the maximum power of the terminal is additionally reduced byapplying the A-MRP suitable for a situation, so that the transmissionpower of the terminal is induced to a level that satisfies requirementsfor a public safety (PS) band, specified in a corresponding country.

Referring to FIG. 9( a), the BS performs signaling on a networksignaling (hereinafter, referred to as NS) value. Information element(hereinafter, referred to as IE) called as additional spectrum emissionis defined in the protocol standard of the current LTE system, and 32NSs is included in the IE. The value of A-MPR corresponding to each NSis defined in TS36.101 that is the 3GPP standard document. That is, eachNS indicates the value of A-MPR corresponding thereto.

Then, the terminal transmits a signal by limiting its transmit poweraccording to the corresponding value of A-MPR.

Specifically, if the terminal receives RBs for multi-clustertransmission in a single component carrier, which are allocated from theBS through its transceiver and then receives an NS value, the terminaltransmits a signal by limiting the maximum transmit power according tothe MPR indicated by the NS value.

Referring to FIG. 9( b), the BS transmits a master information block(MIB) and a system information block (SIB). The SIB may contain at leastone of information on an operating band, information on an uplink (UL)bandwidth and information on a carrier frequency. The information on theUL bandwidth may contain information on the number of RBs.

The information on the operating band may contain information shown inthe following table.

TABLE 4 E-UTRA Operating Uplink Operating Band Downlink Operating BandDuplex Band F_(UL) _(—) _(low)-F_(UL) _(—) _(high) F_(DL) _(—)_(low)-F_(DL) _(—) _(high) Mode 1 1920 MHz-1980 MHz 2110 MHz-2170 MHzFDD 2 1850 MHz-1910 MHz 1930 MHz-1990 MHz FDD 3 1710 MHz-1785 MHz 1805MHz-1880 MHz FDD 4 1710 MHz-1755 MHz 2110 MHz-2155 MHz FDD 5 824 MHz-849MHz 869 MHz-894 MHz FDD 6 830 MHz-840 MHz 875 MHz-885 MHz FDD 7 2500MHz-2570 MHz 2620 MHz-2690 MHz FDD 8 880 MHz-915 MHz 925 MHz-960 MHz FDD9 1749.9 MHz-1784.9 MHz 1844.9 MHz-1879.9 MHz FDD 10 1710 MHz-1770 MHz2110 MHz-2170 MHz FDD 11 1427.9 MHz-1447.9 MHz 1475.9 MHz-1495.9 MHz FDD12 699 MHz-716 MHz 729 MHz-746 MHz FDD 13 777 MHz-787 MHz 746 MHz-756MHz FDD 14 788 MHz-798 MHz 758 MHz-768 MHz FDD 15 Reserved - Reserved -FDD 16 Reserved - Reserved - FDD 17 704 MHz-716 MHz 734 MHz-746 MHz FDD18 815 MHz-830 MHz 860 MHz-875 MHz FDD 19 830 MHz-845 MHz 875 MHz-890MHz FDD 20 832 MHz-862 MHz 791 MHz-821 MHz FDD 21 1447.9 MHz-1462.9 MHz1495.9 MHz-1510.9 MHz FDD 22 3410 MHz-3490 MHz 3510 MHz-3590 MHz FDD 232000 MHz-2020 MHz 2180 MHz-2200 MHz FDD 24 1626.5 MHz-1660.5 MHz 1525MHz-1559 MHz FDD 25 1850 MHz-1915 MHz 1930 MHz-1995 MHz FDD . . . 331900 MHz-1920 MHz 1900 MHz-1920 MHz TDD 34 2010 MHz-2025 MHz 2010MHz-2025 MHz TDD 35 1850 MHz-1910 MHz 1850 MHz-1910 MHz TDD 36 1930MHz-1990 MHz 1930 MHz-1990 MHz TDD 37 1910 MHz-1930 MHz 1910 MHz-1930MHz TDD 38 2570 MHz-2620 MHz 2570 MHz-2620 MHz TDD 39 1880 MHz-1920 MHz1880 MHz-1920 MHz TDD 40 2300 MHz-2400 MHz 2300 MHz-2400 MHz TDD 41 2496MHz-2690 MHz 2496 MHz-2690 MHz TDD 42 3400 MHz-3600 MHz 3400 MHz-3600MHz TDD 43 3600 MHz-3800 MHz 3600 MHz-3800 MHz TDD

Here, the F_(UL) _(—) _(low) means the lowest frequency in the uplinkoperating band, and the F_(UL) _(—) _(high) means the highest frequencyin the uplink operating band. The F_(DL) _(—) _(low) means the lowestfrequency in the downlink operating band, and the F_(DL) _(—) _(high)means the highest frequency in the downlink operating band.

Meanwhile, the terminal can identify that the UL allocated to transmit asignal belongs to a specific class of the CA band classes in Table 2,using the system information (SI) described above. Then, the terminalmay transmit the signal by limiting the maximum transmit power accordingto the MPR recognized by the terminal, without considering the A-MPRthrough the NS. That is, additional ACLR and SE received through the NSmay not be considered.

As can be seen with reference to FIG. 10, the terminal may transmit thesignal by limiting the maximum transmit power according to the MPRrecognized by the terminal, without the NS performed from the BS. Thismeans that when the UL resource allocated from the BS is a generaloperating band which does not requires the NS performed by the BS, themaximum transmit power may be limited according to the MPR recognized bythe terminal.

Hereinafter, a single carrier-frequency division multiple access(SC-FDMA) transmission scheme and the MPR required in the SC-FDMA willbe described.

SC-FDMA

FIG. 11 is a block diagram illustrating an SC-FDMA transmission schemethat is an uplink access scheme employed in the 3GPP LTE.

SC-FDMA is employed in the uplink of LTE. Here, the SC-FDMA is a schemesimilar to OFDM, but can reduce power consumption of a portable terminaland cost of a power amplifier by decreasing a peak to average powerratio (PAPR).

The SC-FDMA is a scheme similar to the OFDM in which a signal is dividedinto sub-bands to be transmitted through sub-carriers using fast Fouriertransform (FFT) and inverse-FFT (IFFT). The SC-FDMA is identical to theconventional OFDM scheme in that a guard interval (cyclic prefix) isused so that it is possible to utilize a simple equalizer in thefrequency domain with respect to inter-symbol interference (ISI).However, the power efficiency of a transmitter has been improved bydecreasing the PAPR at a transmitter terminal by about 2 to 3 dB usingan additional unique technique.

That is, the problem of the conventional OFDM receiver is that signalscarried by each sub-carrier on a frequency axis are converted intosignals on a time axis by the IFF. Since parallel equal operations areperformed in the IFFT, an increase in the PAPR occurs.

Referring to FIG. 11, to solve such a problem, a discrete Fouriertransform (DFT) 12 is first performed on information before a signal ismapped to a sub-carrier in the SC-FDMA. Sub-carrier mapping 13 isperformed on a signal spread (or precoded in the same meaning) by theDFT, and the signal subjected to the sub-carrier mapping is convertedinto a signal in the time axis by performing an IFFT 14.

In this case, unlike the OFDM, the PAPR of a signal in the time domainafter the IFFT 14 is not increased so much by the correlation among theDEF 12, the sub-carrier mapping 13 and the IFFT 14, and thus the SC-FDMAis advantageous in terms of transmission power efficiency.

That is, a transmission scheme in which the IFFT is performed after DFTspreading is referred to as the SC-FDMA.

As such, the SC-FDMA has a similar structure to the OFDM, therebyobtaining the signal strength for a multi-path channel, and the SC-FDMAcompletely prevents the PAPR from being increased through the throughthe IFFT in the conventional OFDM, thereby enabling the use of a poweramplifier. Meanwhile, the SC-FDMA may also be called as DEF spread OFDM(DEF-s-OFDM).

That is, the PAPR or cubic metric (CM) may be decreased in the SC-FDMA.When the SC-FDMA transmission scheme is used, it is possible to avoid anon-linear distortion period of the power amplifier, and thus thetransmission power efficiency can be improved in an UE of which powerconsumption is limited. Accordingly, it is possible to increase a userthroughput.

Meanwhile, the standardization of the LTE-A more improved than the LTEhas been actively performed in the 3GPP. In the process of standardizingthe LTE-A, the SC-FDMA-based scheme and the OFDM scheme competed witheach other, but a clustered DEF-s-OFDM scheme that allows non-contiguousresource allocation has been employed.

Hereinafter, the LTE-A system will be described in detail.

FIG. 12 is a block diagram a clustered discrete Fouriertransform-spread-orthogonal frequency division multiplexing (DFT-s-OFDM)transmission method employed as an uplink access method in theLTE-advanced standard.

The important feature of the clustered DFT-s-OFDM is that it is possibleto flexibly cope with a frequency selective fading environment byenabling frequency selective resource allocation.

In the clustered DFT-s-OFDM scheme employed as the uplink access schemeof the LTE-A, the non-contiguous resource allocation is alloweddifferently from the SC-FDMA that is an uplink access scheme of theconventional LTE, and thus transmitted uplink data can be divided intoseveral cluster units.

That is, the LTE system maintains a single carrier characteristic in theUL. On the other hand, the LTE-A allows a case in which data subjectedto DFT-precoding is non-contiguously allocated on the frequency axis orthe PUSCH and PUCCH are transmitted at the same time. In this case, itis difficult to maintain the single carrier characteristic.

FIG. 13 illustrates a scenario in which a PUSCH is transmitted by beingdivided into several cluster units in a single component carrier. FIG.14 illustrates an adjacent channel leakage ratio (ACLR). FIGS. 15A to15D illustrate simulations respectively obtained by using quadraturephase-shift keying (QPSK) and 16-quadrature amplitude modulation (QAM),and illustrate MPRs according to the simulations.

As can be seen with reference to FIG. 13, there is shown an example inwhich the PUSCH is transmitted by being allocated to several RBs whenthe single component carrier has 100 RBs, i.e., 20 MHz. The number andposition of the allocated RBs are moved from the end to center of thefrequency axis. In this case, the worst scenario is that the smallestnumber of RBs are allocated to both ends of the band.

First, before performing a simulation, parameters used in the simulationwill be described.

-   -   The channel band uses a band compatible in 3GPP Release 8 and 9.    -   The modulation scheme is QPSK/16-QAM.    -   The modulator impairments are as follows.        -   I/Q imbalance: 25 dBc        -   Carrier leakage: 25 dBc        -   Counter IM3: 60 dBc

Here, the I/Q imbalance is I/Q inequality, which means that the I/Qimbalance acts as spreading between symmetric subcarriers and causesperformance degradation. In this case, the unit dBc represents therelative size of power based on the size in the power of a carrierfrequency. The carrier leakage is an additional sinusoidal (sine) wavehaving the same frequency as a modulation carrier frequency. The counterIM3 (counter inter-modulation distortion) represents an element causedby components such as a mixer and an amplifier in an RF system.

ACLR requirements are defined as shown in the following table.

TABLE 5 Channel Band (Measurement Band) 1.4 MHz 3.0 MHz 5 MHz 10 MHz 15MHz 20 MHz UTRA_(ACLR1) 33 dB 33 dB 33 dB 33 dB 33 dB 33 dB Adjacent+0.7+BW_(UTRA)/2 +1.5+BW_(UTRA)/2 +2.5+BW_(UTRA)/2 +5+BW_(UTRA)/2+7.5+BW_(UTRA)/2 +10+BW_(UTRA)/2 Center or or or or or or Frequency−0.7−BW_(UTRA)/2 −1.5−BW_(UTRA)/2 −2.5−BW_(UTRA)/2 −5−BW_(UTRA)/2−7.5−BW_(UTRA)/2 −10−BW_(UTRA)/2 Offset (MHz) UTRA_(ACLR2) — — 36 dB 36dB 36 dB 36 dB Adjacent — — +2.5+3*BW_(UTRA)/2 +5+3*BW_(UTRA)/2+7.5+3*BW_(UTRA)/2 +10+3*BW_(UTRA)/2 Center or or or or Frequency−2.5−3*BW_(UTRA)/2 −5−3*BW_(UTRA)/2 −7.5−3*BW_(UTRA)/2 −10−3*BW_(UTRA)/2Offset (MHz) E-UTRA 1.08 MHz 2.7 MHz 4.5 MHz 9.0 MHz 13.5 MHz 18 MHzChannel Measurement Band UTRA 3.84 MHz 3.84 MHz 3.84 MHz 3.84 MHz 3.84MHz 3.84 MHz 5 MHz Channel Measurement Band UTRA 1.28 MHz 1.28 MHz 1.28MHz 1.28 MHz 1.28 MHz 1.28 MHz 1.6 MHz Channel Measurement Band

In Table 5, the BW_(UTRA) means a channel bandwidth for UTRA.

In Table 5, in a case where an adjacent channel 1402 is used for thepurpose of UTRA as shown in FIG. 14 when the terminal transmits a signalin an E-UTRA channel 1401, the UTRA_(ACLR1) is a rate in which thesignal is leaked to the adjacent channel 1402, i.e., UTRA channel. Thatis, the UTRA_(ACLR1) is an adjacent channel leakage rate (ACLR). In acase where a channel 1403 positioned adjacent to the adjacent channel1402 is used for the purpose of UTRA as shown in FIG. 14 when theterminal transmits a signal in the E-UTRA channel 1401, the UTRA_(ACLR2)is a rate in which the signal is leaked to the adjacent channel 1403,i.e., UTRA channel. That is, the UTRA_(ACLR2) is an ACLR. In a casewhere a channel 1404 positioned adjacent to the adjacent channel 1404 isused for the purpose of UTRA as shown in FIG. 14 when the terminaltransmits a signal in the E-UTRA channel 1401, the E-UTRA_(ACLR) is arate in which the signal is leaked to the adjacent channel 1404, i.e.,UTRA channel. That is, the UTRA_(ACLR) is an ACLR.

The value of the MPR represents a general SEM that a frequency must notinterfere when the channel is distant by a certain frequency distancefrom the outside of a given channel band. The value of MPR for Release 8or 9 is defined as shown in the following table.

TABLE 6 Spectrum Emission Limit for Channel Band (dBm) ΔF_(OOB) 1.4 3.05 10 15 20 Measure- (MHz) MHz MHz MHz MHz MHz MHz ment Band ±0-1 −10 −13−15 −18 −20 −21 30 kHz  ±1-2.5 −10 −10 −10 −10 −10 −10 1 MHz ±2.5-2.8−25 −10 −10 −10 −10 −10 1 MHz ±2.8-5  −10 −10 −10 −10 −10 1 MHz ±5-6 −25−13 −13 −13 −13 1 MHz  ±6-10 −25 −13 −13 −13 1 MHz ±10-15 −25 −13 −13 1MHz ±15-20 −25 −13 1 MHz ±20-25 −25 1 MHz

Here, the ΔF_(OOB) is an abbreviation for Frequency of Out Of Bandemission, and represents a frequency when the frequency is emitted outof the channel band. The dBm is a unit of power (Watt), and 1 mW=0 dBm.

The general spurious emission (SE) that a frequency must not interfereaccording to the frequency range is defined as shown in the followingtable.

TABLE 7 Frequency Band Maximum Level Measurement Band 9 kHz ≦ f < 150kHz −36 dBm 1 kHz 150 kHz ≦ f < 30 MHz −36 dBm 10 kHz 30 MHz ≦ f < 1000MHz −36 dBm 100 kHz 1 GHz ≦ f < 12.75 GHz −30 dBm 1 MHz

Hereinafter, the result obtained by performing the simulations, based onthe simulation parameters described above, will be described. In thiscase, based on the simulation result, the MPR required in the singlecomponent carrier is defined as NS_(—)01, and the A-MPR required whenother requirements additionally exist is defined as NS_XX.

Referring to FIG. 15A, there is shown a simulation result when multipleclusters are simultaneously transmitted using a QPSK modulation schemeunder the situation of a single component carrier. Specifically, whenthe allocation ratio is within a range from 0 to 0.1, the MPR of amaximum of about 7.6 dB is required. As such, the MPR according to thesimulation result of FIG. 15A can be defined as NS_(—)01 if QPSKmodulation is used.

Referring to FIG. 15B, there is shown a simulation result when multipleclusters are simultaneously transmitted using a 16-QAM modulation schemeunder the situation of a single component carrier. According to thesimulation result, when the allocation ratio is within a range from 0 to0.1, the MPR of a maximum of about 8 dB is required. The MPR accordingto the simulation result of FIG. 15B is defined as NS_(—)01 if 16 QAMmodulation is used. However, in order to consider results of QPSK, theMPR according to the simulation result of FIG. 15B can be defined asNS_(—)01.

The MPR required to reduce the ACLR, SEM and SE has be derived from thesimulation results shown in FIGS. 15A and 15B. In a case where thesignaling is performed as the NS_(—)01, the terminal must apply othervalues of MPR according to the allocation ratio. The values of MPRaccording to the allocation ratio are defined as shown in the followingtable.

Table 8 shows values of MPR, required when multiple clusters aresimultaneously transmitted using the single component carrier in a casewhere the signaling is performed from the BS to the terminal as theNS_(—)01.

TABLE 8 A = N_(RB) _(—) _(alloc)/N_(RB) _(—) _(agg) 0 0.1 0.4 0.7 1 MaskLimit (dB) 8.0 7.0 4.0 3.3 3.3

$\begin{matrix}{{{MPR} = {\left( {8.0 - {1.0*A}} \right){dB}}},} & {0 < A \leq 0.1} \\{{= {\left( {8.0 - {10*A}} \right){dB}}},} & {{0.1 < A} = 0.4} \\{{= {\left( {4.96 - {2.33*A}} \right){dB}}},} & {{0.4 < A} = 0.7} \\{{= {3.3\mspace{14mu}{dB}}},} & {{0.7 < A} = 1.0}\end{matrix}$

Here, the N_(RB) _(—) _(agg) denotes the number of RBs aggregated in theaggregation channel band. The N_(RB) _(—) _(alloc) denotes the totalnumber of RBs simultaneously transmitted in the configuration of theaggregation channel band. Alternately, the N_(RB) _(—) _(alloc) denotesthe sum of activated RBs, although it is not indicated that all clustersare considered.

Referring to FIG. 15C, there is shown a simulation result when multipleclusters are simultaneously transmitted by using the QPSK modulationscheme under the situation of the single component carrier and byconsidering additional SE/SEM of NS_(—)04. According to the simulationresult, when the allocation ratio is within a range from 0 to 0.1, theMPR of a maximum of about 11.2 dB is required. As such, the MPRaccording to the simulation result of FIG. 15C can be defined as a valuefor NS_(—)04 if QPSK modulation is used.

Referring to FIG. 15D, there is shown a simulation result when multipleclusters are simultaneously transmitted using the 16-QAM modulationscheme under the situation of the single component carrier. According tothe simulation result, when the allocation ratio is within a range from0 to 0.1, the MPR of a maximum of about 11.2 dB is required. As such,the MPR according to the simulation result of FIG. 15D can be defined asNS_(—)04 if 16 QAM modulation is used. However, in order to considerresults of QPSK, the MPR according to the simulation result of FIG. 15Dcan be defined as NS_(—)0.

As can be seen from the simulation results shown in FIGS. 15C and 15D,the terminal must apply other values of MPR according to the allocationratio.

FIG. 16 illustrates MPRs according to simulation results, when multipleclusters are simultaneously transmitted through a single componentcarrier.

Unlike FIG. 15, MPR_required according to the allocation ratioA_(RB)=(N_(RB) _(—) _(alloc)/N_(RB) _(—) _(agg)) is shown in FIG. 16 bysimultaneously considering the QPSK modulation scheme and the 16-QAMmodulation scheme. Meanwhile, the value of MPR shown in FIG. 16 may be avalue previously stored in the terminal. Therefore, when the band of theallocated UL resource is a general operating band that does not requirethe NS, the transmission power may be limited using the value of MPRpreviously stored in the terminal. Meanwhile, if a specific NS isreceived, the UE can limit a maximum transmission power according toA-MPR mask.

TABLE 9 A = N_(RB) _(—) _(alloc)/N_(RB) _(—) _(agg) 0 0.1 0.4 0.7 1 MPRMask Limit (dB) 8.0 7.0 4.0 33 3.3

$\begin{matrix}{{{MPR} = {\left( {8.0 - {1.0*A}} \right){dB}}},} & {0 < A \leq 0.1} \\{{= {\left( {8.0 - {10*A}} \right){dB}}},} & {{0.1 < A} = 0.4} \\{{= {\left( {4.96 - {2.33*A}} \right){dB}}},} & {{0.4 < A} = 0.7} \\{{= {3.3\mspace{14mu}{dB}}},} & {{0.7 < A} = 1.0}\end{matrix}$

Upper table 9 is the required MPR mask from the simulation results forgeneral unwanted emission as FIGS. 15A and 15B

Each waveform includes two clusters in which RBs have various bandwidthsand the same power spectrum density. The position and band of the RB arearbitrary. The MPR for each waveform is calculated in consideration ofthe general SEM, the ACLR and the general SE. That is, in a case wherethe UL resource allocated from the BS exists in the channel band 1401for the E-UTRA, the value of MPR is calculated the UTRA_(ACLR1) andUTRA_(ACLR2) for the channel band for the E-UTRA and the two adjacentchannels 1402 and 1403. In a case where the UL resource allocated fromthe BS exists in the channel band 1401 for the E-UTRA, the value of MPRis calculated in consideration of the E-UTRA_(ACLR) for the adjacentchannel 1404, i.e., the channel for the E-UTRA. The value of MPR iscalculated in consideration of the general SE that a frequency must notinterfere when the channel is distant by a certain frequency distancefrom the outside of a given channel band. The value of the MPR iscalculated in consideration of the general SE that a frequency must notinterfere according to the frequency range. Meanwhile, the result 1 maybe modified like the final plan shown in FIG. 16. Hereinafter, the finalplan will be described.

The MPR of the maximum output power for the transmission of multipleclusters, with respect to Class A in an intra-band contiguous CA band,is as follows. Alternatively, the MPR of the maximum output power forthe transmission of multiple clusters in the single component carrier isas follows.MPR=CEIL{M _(A),0.5}

Here, the CEIL {M_(A), 0.5} means a function of rounding off the MPR asa unit of 0.5 dB. That is, MPR ε {3.0, 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.07.5 8.0}.

$\begin{matrix}{{{MPR} = {\left( {8.0 - {10.12*A}} \right){dB}}},} & {0 < A \leq 0.33} \\{{= {\left( {5.67 - {3.07*A}} \right){dB}}},} & {{0.33 < A} = 0.77} \\{{= {3.31\mspace{14mu}{dB}}},} & {{0.77 < A} = 1.0}\end{matrix}$

The value of MPR is calculated in consideration of SE.

The value of the MPR may be a value previously stored in the terminal,although it is not indicated through the NS performed from the BS. Thatis, when the UL resource allocated from the BS is a general operatingband which does not requires the NS, the value of MPR previously storedin the terminal may be used.

The exemplary embodiments described above may be implemented usingvarious means. For example, the exemplary embodiments may be implementedby hardware, firmware, software, or combination thereof.

According to the implementation using the hardware, the method accordingto the exemplary embodiments may be implemented using at least one ofapplication specific integrated circuits (ASICs), digital signalprocessors (DSPs), digital signal processing devices (DSPDs),programmable logic devices (PLDs), field programmable gate arrays(FPGAs), processors, controllers, etc.

According to the implementation using the firmware or software, themethod according to the exemplary embodiments may be implemented in theform of a module, procedure or function performing functions andoperations described above. Software codes may be stored in a memoryunit and executed by a processor. The memory unit may be located in theinside or outside of the processor, and communicate data with theprocessor using various means known in the art.

FIG. 17 is a configuration block diagram of a terminal 100 according toan exemplary embodiment.

As shown in FIG. 17, the terminal 100 includes a storage means 110, acontroller 120 and a transceiver 130.

The storage means 110 stores the methods shown in FIGS. 10 to 16.

The controller 120 individually controls the storage means 110 and thetransceiver 130. Specifically, the controller 120 performs the methodsstored in the storage means 110. If the transceiver 130 receives RBsallocated to transmit multiple clusters using a single component carrierfrom the BS and receives an NS value, the controller 120 controls thetransceiver 130 to transmit a signal by limiting the maximum transmitpower according to the MPR indicated by the NS value.

The present invention may be applied to terminals, base stations orother equipments in a wireless mobile communication system.

The foregoing embodiments and advantages are merely exemplary and arenot to be construed as limiting the present disclosure. The presentteachings can be readily applied to other types of apparatuses. Thisdescription is intended to be illustrative, and not to limit the scopeof the claims. Many alternatives, modifications, and variations will beapparent to those skilled in the art. The features, structures, methods,and other characteristics of the exemplary embodiments described hereinmay be combined in various ways to obtain additional and/or alternativeexemplary embodiments.

As the present features may be embodied in several forms withoutdeparting from the characteristics thereof, it should also be understoodthat the above-described embodiments are not limited by any of thedetails of the foregoing description, unless otherwise specified, butrather should be construed broadly within its scope as defined in theappended claims, and therefore all changes and modifications that fallwithin the metes and bounds of the claims, or equivalents of such metesand bounds are therefore intended to be embraced by the appended claims.

What is claimed is:
 1. A method of reducing transmission power, themethod performed by a user equipment and comprising: calculating amaximum power reduction (MPR) on a maximum output power for transmissionwith non-contiguous resource allocation in a single component carrier;and transmitting a signal based on the MPR, wherein the MPR iscalculated differently depending on a ratio A which is a ratio of anumber of simultaneously transmitted resource blocks in a channelbandwidth (NRB_alloc) to a number of aggregated resource blocks in afully allocated aggregated channel bandwidth (NRB_agg), wherein the MPRis calculated using a first equation when the ratio A is greater than 0and less than or equal to 0.33, wherein the MPR is calculated using asecond equation when the ratio A is greater than 0.33 and less than orequal to 0.77, and wherein the MPR is calculated using a third equationwhen the ratio A is greater than 0.77 and less than or equal to
 1. 2.The method of claim 1, wherein the MPR is determined as a followingequation: MPR=CEIL {MA, 0.5}, the CEIL being a function of rounding upby 0.5.
 3. The method of claim 2, wherein the first equation is afollowing equation A:MA=(8.0−10.12*A).  [equation A]
 4. The method of claim 2, wherein thesecond equation is a following equation B:MA=(5.67−3.07*A).  [equation B]
 5. The method of claim 2, wherein thethird equation is a following equation C:MA=(3.31).  [equation C]
 6. A user equipment for transmitting a signalfor reducing transmission power, the user equipment comprising: atransceiver configured to transceive the signal; a controller configuredto: calculate a maximum power reduction (MPR) on a maximum output powerfor transmission with non-contiguous resource allocation in a singlecomponent carrier, and transmit a signal based on the MPR, wherein theMPR is calculated differently depending on a ratio A which is a ratio ofa number of simultaneously transmitted resource blocks in a channelbandwidth (NRB_alloc) to a number of aggregated resource blocks in afully allocated aggregated channel bandwidth (NRB_agg), wherein the MPRis calculated using a first equation when the ratio A is greater than 0and less than or equal to 0.33, wherein the MPR is calculated using asecond equation when the ratio A is greater than 0.33 and less than orequal to 0.77, and wherein the MPR is calculated using a third equationwhen the ratio A is greater than 0.77 and less than or equal to
 1. 7.The user equipment of claim 6, wherein the MPR is determined as afollowing equation: MPR=CEIL {MA, 0.5}, the CEIL being a function ofrounding up by 0.5.
 8. The user equipment of claim 7, wherein the firstequation is a following equation A:MA=(8.0−10.12*A).  [equation A]
 9. The user equipment of claim 7,wherein the second equation is a following equation B:MA=(5.67−3.07*A).  [equation B]
 10. The user equipment of claim 7,wherein the third equation is a following equation C:MA=(3.31).  [equation C]